"The system was established to provide the President of the United States with an expeditious method of communicating with the American public in the event of war, threat of war, or grave national crisis."[1] The Emergency Broadcast System replaced CONELRAD on August 5, 1963.[2] In later years, it was expanded for use during peacetime emergencies at the state and local levels.[1]

Although the system was never used for a national emergency, it was activated more than 20,000 times[citation needed] between 1976 and 1996 to broadcast civil emergency messages and warnings of severe weather hazards.

The release of the EAN by the Aerospace Defense Command or the Federal Preparedness Agency would initiate a process by which the common carriers would link otherwise independent networks such as ABC, CBS, and NBC into a single national network that even independent stations could receive programming from. "Broadcast stations would have used the two-tone Attention Signal on their assigned broadcast frequency to alert other broadcast stations to stand by for a message from the President."[1] The transmission of programming on a broadcast station's assigned frequency, and the fact that television networks/stations and FM radio stations could participate, distinguished EBS from CONELRAD. EBS radio stations would not necessarily transmit on 640 or 1240 on the AM dial, and FM radio and television would carry the same audio program as AM radio stations did.

Actual activations originated with a primary station, which would transmit the Attention Signal(help·info). The Attention Signal most commonly associated with the system was a combination of the sine waves of 853 and 960 Hz, an interval suited to getting the audience's collective attention due to its unpleasantness on the human ear. Decoders at relay stations would sound an alarm, alerting the station operator to the incoming message. Then, each relay station would broadcast the alert tone and rebroadcast the emergency message from the primary station.

A nationwide activation of the EBS was called an Emergency Action Notification (EAN), and was the only activation that stations were not allowed to ignore; the Federal Communications Commission made local civil emergencies and weather advisories optional (except for stations that agreed to be the "primary" source of such messages).

To activate the EAN protocol, the AP and UPI wire services would notify stations with a special message. It began with a full line of X's, and a bell inside the Teletype machine would sound ten times. To avoid abuse and mistakes, the message included a confirmation password which changed daily. Stations that subscribed to one of the wire services were not required to activate the EBS if the activation message did not have proper confirmation.

Despite these safeguards, the system was accidentally activated at 9:33 a.m. Eastern Standard Time on February 20, 1971.[3] Teletype operator W. S. Eberhardt "played the wrong tape" during a test, which sent an activation message authenticated with the codeword "hatefulness" through the entire system, ordering stations to cease regular programming and broadcast the alert of a national emergency.[4] A cancellation message was sent at 9:59 a.m. EST, but it used an incorrect codeword. A cancellation message with the correct word, "impish", was not sent until 10:13 a.m. EST[4] After 40 minutes and six incorrect cancellation messages, the accidental activation was terminated.

This false alarm demonstrated major flaws in the EBS. Many stations had not received the alert but more importantly, the vast majority of those that did either ignored it (because it came at the time of a scheduled test), or did not know what to do in an emergency.[4] Some stations followed the procedures for an activation, but cancelled them prematurely. It is estimated that only 20% of the stations that received the activation followed the procedures completely.[3] While several stations went off the air, the one best remembered was WOWO in Fort Wayne, Indiana, which broadcast the 1971 events as they happened, a recording of which has become available. Another recording of how the error sounded on WCCO-AM in Minneapolis/Saint Paul, Minnesota can be heard on RadioTapes.com.

Numerous investigations were launched, and several changes were made to the EBS. Among them, the on-air alert announcement was streamlined, eliminating one version of the script that warned the audience of an imminent attack against the country (the WOWO broadcast above does not contain the reference to an attack).

Though it was never used, the FCC's EBS plan involved detailed procedures for stations to follow during an EAN. It included precise scripts that announcers were to read at the outset of the emergency, as well as whenever detailed information was scarce. Among other things, citizens were instructed not to use the telephone, but rather continue listening to broadcast stations for information.

The initial scripted announcement was: "We interrupt this program. This is a national emergency. The President of the United States or his designated representative will appear shortly over the Emergency Broadcast System."

As official information began to emerge from various sources, non-primary stations were to broadcast it according to the following priority list:

A presidential message was always required to be aired live during an EAN. For other information, stations were to follow the priority list to decide what should be disseminated first. Lower priority official programming was to be recorded for the earliest available rebroadcast.

Participation in EAN emergency broadcasting was done with the "voluntary cooperation" of each station (as noted in the classic test announcement). Stations that were not prepared to be part of the national EBS network were classified as "non-participating" by the FCC. During an EAN, a non-participating station was required to advise listeners/viewers to tune elsewhere to find emergency bulletins. The station's transmitter would then be turned off. Non-participating stations had to remain off-the-air until the EAN was terminated. Under no circumstances could any broadcast station continue with normal programming during a national emergency.

Until the system was superseded, radio and television stations were required to perform a Weekly Transmission Test Of The Attention Signal and Test Script at random days and times between 8:30 a.m. and local sunset. Stations were required to perform the test at least once a week, and were only exempt from doing so if they had activated the EBS for a state or local emergency, or participated in a coordinated state or local EBS test during the past week. Additionally, stations were required to log tests they received from each station they monitored for EBS messages. This served as an additional check, as these stations could expect to hear a weekly test from each source. Failure to receive a signal at least once a week meant that either the monitored station was having a problem transmitting the alert signal, or the monitoring station was having a problem receiving it.

Early on, tests and activations were initiated in a similar way to CONELRAD tests. Primary stations would turn their transmitters off for five seconds, back on for five seconds, off for five seconds more, then would go back on air and transmit a 1000 Hz tone for 15 seconds to alert secondary stations. This quick off-and-on became known to broadcast engineers as the "EBS Stress Test", as older transmitters would sometimes fail after the quick cycling on and off.[5] This became unnecessary as broadcast technology advanced and the two-tone alarm was developed.

Beginning in 1976, the old CONELRAD signaling method (the "EBS Stress Test") was scrapped in favor of the following procedure:[6]

1. Normal programming was suspended, though tests were typically done during commercial breaks for continuity reasons. Television stations would transmit a video slide such as the one illustrated at the beginning of the article; numerous designs were available over the years. One of the following announcements was transmitted:

"This is a test. For the next sixty (or thirty) seconds, this station will conduct a test of the Emergency Broadcast System. This is only a test."

"(name of host station in a particular market) is conducting a test of the Emergency Broadcast System. This is only a test." (mainly radio stations used this particular announcement)

"This is a test. (Name of Host Station) is conducting a test of the Emergency Broadcast System. This is only a test."

"This is a test. This station is conducting a test of the Emergency Broadcast System. This is only a test."

"The following is a test of the Emergency Broadcast System."

"This is a test of the Emergency Broadcast System. Important information will follow this tone."

Alternatively, the name "Emergency Broadcasting System" could also be used in the announcement.

2. The Attention Signal was transmitted from the EBS encoder for 20 to 25 seconds. At the special request of the FCC, however, this step was occasionally (though rarely) skipped.[citation needed] In mid-1995, a new rule was put in place that gave stations the option to transmit the attention signal for anywhere from eight to 25 seconds.

3. The announcement written below (depending on the variation) was transmitted. The first part read:

"This is a test of the Emergency Broadcast System. The broadcasters of your area in voluntary cooperation with the FCC and other authorities (or, in later years, "federal, state and local authorities") have developed this system to keep you informed in the event of an emergency."

"This is a test of the Emergency Broadcast System. Broadcasters, in cooperation with the FCC and other authorities (or, in later years, "federal, state and local authorities") have developed this system to keep you informed in the event of an emergency."

There were a number of variations for the second half of the statement. During the system's early days, stations other than the designated primary station for an operational area were required to shut down in the event of an emergency (reminiscent of the CONELRAD days), and the message was a variation of:

"If this had been an actual emergency, you would have been instructed to tune to one of the broadcast stations in your area."

"If this had been an actual emergency, you would have been instructed where to tune in your area for news and official information."

By the early 1980s, it was easier for stations to record and relay messages from a primary station, and the risk of hostile bombers using broadcast signals to navigate lessened due to the development of ICBMs. As a result, the requirement to shut down during an activation of the system was dropped, and the message became:

"If this had been an actual emergency, the Attention Signal you just heard would have been followed by official information, news, or instructions."

As the EBS was about to be replaced by its successor, the Emergency Alert System, some stations used the following message:

"This station is testing its Emergency Broadcast System equipment. The EBS will soon be replaced with the Emergency Alert System; the EAS will provide timely emergency warnings."

4. The test concluded with one of the following phrases:

"(Sponsoring station) serves (the name of operational area). This concludes this test of the Emergency Broadcast System."

"Stations of the (the name of the station public broadcasting network, for example: South Dakota Public Broadcasting Network) serve all operational areas in (name of state). This concludes this test of the Emergency Broadcast System." (used mostly by statewide public television and/or radio networks)

"This station serves the (name of operational area). This concludes this test of the Emergency Broadcast System."

"(Sponsoring station) serves (the name of operational area). This concludes this Emergency Broadcast System Test." (mainly used by stations that used the This Station is testing its Emergency Broadcast System equipment variant)

These variations were heard in different parts of the country throughout the years depending on FCC regulations at the time, local preferences, and whether the specific station performing the test was a primary EBS station or not. At least one version made explicit reference to an attack on the United States as being a possible scenario for EBS activation.

The announcement text was mandated by the FCC. Stations had the option of either reading the test script live, or using recorded versions. WHEN radio in Syracuse, New York and WGR radio in Buffalo, New York both had a sung version of the most common script.[7] There was also a version done by Los Angeles-based Cheap Radio Thrills, as well as another by the comedy team of Bob and Ray. The FCC declared it illegal to sing the test message, or read it as a joke. However, it was acceptable to read it in another language (for example, French or Spanish), if a station broadcast in a language other than English. Copies of the warning message script had a note saying that it was acceptable to broadcast in any other language, so long as it was broadcast in English as well.[8] Usually the post-test recorded announcement began with the phrase, "This has been a test of the Emergency Broadcast System...", followed by the here-in-above stated recitations.

The purpose of the test was to allow the FCC and broadcasters to verify that EBS tone transmitters and decoders were functioning properly. In addition to the weekly test, test activations of the entire system were conducted periodically for many years. These tests showed that about 80% of broadcast outlets nationwide would carry emergency programming within a period of five minutes when the system was activated.

The weekly broadcasts of the EBS attention signal and test script made it a significant part of the American cultural fabric of its time, and became the subject of a great number of jokes and skits, such as the sung versions of the test script in the late 1970s. In addition, many people have testified to being frightened by the test patterns and attention signal as children, and even more so by actual emergencies.